Sirius B success !

[NGC 1502]

At long last I’ve managed to spot the ‘pup’, the white dwarf companion to Sirius. Although this has been successfully done with a good 4” refractor under excellent conditions, I’d never achieved it with my 10” Dob. But at my local club recently I was encouraged by an experienced member that he had seen the pup with his 10”, and another member pointed out that the separation is almost at maximum, so it’s a good time to try.

So earlier this evening, with Sirius due south and therefore at its highest, my scope cooled and colimated, I was chuffed to bits to spot the tiny speck of light trailing east of brilliant Sirius, using 170x. The seeing was variable, and at times the companion could not be seen, but then as the turbulence settled, the pup was fairly easy to see. If the secondary star had been obscured by the diffraction spikes from the Newtonian spider, I would not have been successful, but thankfully that was not the case.

Off out for another session to make the most of a clear night with the moon not up until around 02.30.

Cheers from a satisfied Ed.

 

 

 

 

[orion25]

Congratulations! Sirius B is tricky to get. I haven't seen it yet but I'll keep trying. I'll probably need to use my 180mm Mak to have any chance of detecting it.

[MarsG76]

congrats

[Ibbo!]

Well done.

[Astro Imp]

Great, well done Ed. 

[Stu]

Well done indeed Ed! This remains on my 'still to be seen' list!! 

[Dave1]

Well done, I have yet to see Sirus b, so now i will attempt it!

[cotterless45]

Brilliant , within reach !

[Hayduke27]

I have tried and missed several times recently on this little star!  Congratulations, and this makes me want to go give it another go!

[chiltonstar]

When conditions are right, there it is! Wrong conditions.....not a chance.

Chris

[NGC 1502]

9 hours ago, chiltonstar said:

When conditions are right, there it is! Wrong conditions.....not a chance.

Chris

Hi Chris, indeed I’m sure that’s right. Decent conditions, cooled and collimated scope, Sirius not too far from culmination, very careful focusing, not too low or too high power, not giving up but patiently waiting for the seeing to steady, if using an eyepiece that has poor edge correction then keep Sirius as close as you can to the centre of field of view, are all factors that increase the chances of success.

Another thing is to be looking in the right place :-

The position angle is about 83 degrees. So Sirius B will be a tiny speck east of the brilliant A star. In an undriven Newtonian scope, stars drift out of the field of view on the west or left hand side, so the pup will be to the right of Sirius. If using an SCT or refractor with a diagonal in place, then the view is reversed. Sirius B will be to the left of Sirius A.

Good luck, when you are successful, it’s a great moment ? ...............Ed.

[chiltonstar]

10 minutes ago, NGC 1502 said:

Hi Chris, indeed I’m sure that’s right. Decent conditions, cooled and collimated scope, Sirius not too far from culmination, very careful focusing, not too low or too high power, not giving up but patiently waiting for the seeing to steady, if using an eyepiece that has poor edge correction then keep Sirius as close as you can to the centre of field of view, are all factors that increase the chances of success.

Another thing is to be looking in the right place :-

The position angle is about 83 degrees. So Sirius B will be a tiny speck east of the brilliant A star. In an undriven Newtonian scope, stars drift out of the field of view on the west or left hand side, so the pup will be to the right of Sirius. If using an SCT or refractor with a diagonal in place, then the view is reversed. Sirius B will be to the left of Sirius A.

Good luck, when you are successful, it’s a great moment ? ...............Ed.

With my mak, stars drift to the left (W), same as you have with your newt. For example, see this image of Sirius with The Pup, with the Pup to the E, taken with my 180 Mak.

Chris

 

 

[NGC 1502]

4 hours ago, chiltonstar said:

With my mak, stars drift to the left (W), same as you have with your newt. For example, see this image of Sirius with The Pup, with the Pup to the E, taken with my 180 Mak.

Chris

 

 

Hi Chris, thanks for that, my mistake of course, it’s north / south that will be reversed, not east / west. Your image shows what a tiny pin point of light we are looking for, so easily lost in the glare of brilliant Sirius, especially with the normally encountered poor seeing. Another factor not a problem with a Mak, SCT or refractor is there’s no spider vanes to cause diffraction spikes.

Cheers from Ed.

[25585]

Is the blue toupe' CA?

[chiltonstar]

2 hours ago, 25585 said:

Is the blue toupe' CA?

Shouldn't be CA as it is a nearly CA free scope, and no Barlow was used; I think it is more likely to be an atmospheric refraction effect because of the low altitude of Sirius. It might also arise from the fact that blue light is scattered more than other colours, so the apparent size of Sirius might be slightly larger in blue light than other wavelengths.

Chris

[Paul73]

Yep. Whenever I try, it is a colourful light show! The light hits the atmosphere at a relatively shallow angle and the different wavelengths get refracted by different amounts, splitting the colours. Then it has to get through a LOT of swirling atmosphere befor we try and spot the pup. Similar with a Low Jupiter las night!

I’ve never seen it but keep having a look now and agin.

Paul